set empty object/array for required properties/items

jsonform/gadget_json_generated_form_child.js

@@ -1071,6 +1071,9 @@
       div.setAttribute("data-parent-scope", gadget.element.getAttribute("data-gadget-scope"));
       div.setAttribute("data-json-path", first_path + '/');
       div.setAttribute("data-json-type", type);
+      if (options.required) {
+        div.setAttribute("data-json-required", "true");
+      }
     }
 
     if (schema.info !== undefined) {
@@ -1549,12 +1552,19 @@
     }
 
 
-    // set empty object if default value require this
+    // set empty object/array for required properties/items
     array = g.element
       .querySelectorAll("div[data-parent-scope='" +
                         g.element.getAttribute("data-gadget-scope") + "']");
     for (i = 0; i < array.length; i += 1) {
       path = array[i].getAttribute("data-json-path").slice(0, -1);
+      if (array[i].hasAttribute("data-json-required")) {
+        if (array[i].getAttribute("data-json-type") === "object") {
+          convertOnMultiLevel(multi_level_dict, path, {});
+        } else {
+          convertOnMultiLevel(multi_level_dict, path, []);
+        }
+      }
     }
 
     for (path in options.arrays) {